CVE-2021-3618
High
Description
ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.
SeverityHigh
CVSS7.4
Exploit probability81. percentile2%
Product
F5 Nginx
PublishedMar 23, 2022
Weakness typeCWE-295CWE-295
How to fix
Update
- f5 nginx1.21.0 or later
- sendmail sendmail8.17 or later
- vsftpd_project vsftpd3.0.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| f5 nginx | v < 1.21.0 | 1.21.0 |
| sendmail sendmail | v < 8.17 | 8.17 |
| vsftpd_project vsftpd | v < 3.0.4 | 3.0.4 |
| fedoraproject fedora | 33, 34, 35 | — |
| debian debian_linux | 10.0 | — |
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